CN208128134U - Electromagnetic interference EMI suppression circuit, DC power supply and electric heating utensil - Google Patents

Abstract

The utility model embodiment provides a kind of electromagnetic interference EMI suppression circuit, DC power supply and electric heating utensil, belongs to electromagnetic interference circuit design field.The EMI suppression circuit includes：First capacitor bridges power ground and AC neutral line input terminal；Second capacitor, bridging power ground with exchange firewire input terminal；Third capacitor bridges the exchange firewire input terminal and AC neutral line input terminal of rectification module；First inductance, is connected between power ground and heated object；Second inductance is connected between the direct current cathode output end of rectification module and electric heater；4th capacitor bridges the direct-flow positive pole output end and direct current cathode output end of rectification module；First resistor and second resistance parallel with one another is connected in the connection line of first capacitor and the second capacitor and power ground.Thus by EMI noise reverse conduction to filter out, and EMI surplus of the electric heating utensil under EMI test conduction is improved.

Description

Electromagnetic interference EMI suppression circuit, DC power supply and electric heating utensil

Technical field

The utility model relates to electromagnetic interference circuit design field, more particularly to a kind of electromagnetic interference EMI suppression circuit, DC power supply and electric heating utensil.

Background technique

With the continuous promotion that people pursue quality of the life, electric heating utensil (such as electric cooker etc.) receives vast The favor of Market Consumer.Under the heating mode of electric heating utensil, such as IH (induction heat, electromagnetic heating) mould Formula, usually for safety, utensil bottom or utensil metal shell can be grounded, and the introducing of these ground connection results in additional electricity Heat the EMI problem of utensil.Specifically, during electric heating utensil heats food, although the conversion of a large amount of energy in order to Heat, but when still there is portion of energy to conduct by ground wire to power grid, this be EMI noise main source.

Currently, in the related technology in order to solve heating utensil EMI (electromagnetic interference, electricity Magnetic disturbance) problem, common mode inhibition device would generally be set on firewire or zero curve, to inhibit to draw because of utensil or chassis ground The purpose of the common-mode noise entered.But present inventor found during practicing the application it is above-mentioned in the related technology Technical solution at least there is following defect：

First, common mode inhibition device head is bigger, needs to occupy the limited space of circuit board, causes additional structure empty Between, it is unfavorable for the topology layout and design of product.

Second, common mode inhibition device cost is higher.

Third, common mode inhibition device heating amount is big, leads to the reduction of complete machine thermal conversion efficiency.

4th, EMC electromagnetism of the generated middle low frequency differential mode noise for product during the work of electric heating utensil There is also certain influences for the superiority and inferiority of compatible performance, and the solution without being effectively treated for differential mode noise in the prior art Certainly scheme.

5th, novel electric heating utensil during the work time caused by EMI noise frequency it is larger, can achieve 150KHz or more, so that the common mode inhibition device in the prior art can not well solve the electromagnetic interference of electric heater Problem enables it be difficult to through EMC electromagnetic compatibility test.

As a result, it is a kind of it is low in cost, thermal losses is low, occupancy is small in size and can effectively improve novel electric heating utensil The circuit design of EMI surplus is the popular research direction of current industry.

Utility model content

The purpose of the utility model embodiment another aspect be to provide it is a kind of it is low in cost, thermal losses is low and can effectively mention The DC power supply of the EMI surplus of high electric heating utensil.

To achieve the goals above, on the one hand it is dry to provide a kind of electromagnetism for electric heating utensil for the utility model embodiment EMI suppression circuit is disturbed, which includes electric heater, heated object and the rectification module for electric heater power supply, is somebody's turn to do The exchange firewire input terminal and AC neutral line input terminal of rectification module are separately connected the firewire and zero curve of AC power source, are used for institute The alternating current for stating AC power source is converted to direct current and exports via the direct-flow positive pole output end of the rectification module and direct current cathode End output and the heated object are connected with power ground, and wherein the EMI suppression circuit includes：First capacitor, bridging The power ground and the AC neutral line input terminal；Second capacitor, bridge the power ground with described to exchange firewire defeated Enter end；Third capacitor bridges the exchange firewire input terminal and the AC neutral line input terminal of the rectification module；First Inductance is connected between the power ground and the heated object；Second inductance is connected on the institute of the rectification module It states between direct current cathode output end and the electric heater；4th capacitor, the direct-flow positive pole for bridging the rectification module are defeated Outlet and the direct current cathode output end；First resistor and second resistance, parallel with one another, the first resistor parallel with one another and Two resistance are connected in the connection line of the first capacitor and second capacitor and the power ground.

Optionally, the carrier of the EMI suppression circuit is PCB printed circuit board.

Optionally, the first resistor and the second resistance include Chip-R.

Specifically, the first capacitor and the capacitance size of second capacitor are 100pF-4700pF and described The size of the capacitance of third capacitor is 1 μ F-10 μ F.

In the EMI suppression circuit provided by above-mentioned technical proposal, by bridging power ground and AC neutral line input terminal First capacitor, with bridging power ground with exchange the second capacitor of firewire input terminal, and be connected on power ground and heated object Between the first inductance, and form low pass RLC filter together with the concatenated parallel resistance of shunt capacitance, Novel electric can be added Hot utensil during the work time caused by high frequency common mode noise from power interface reverse leading to EMI suppression circuit, and by its It filters out, it is insufficient to efficiently solve the problems, such as that common mode conducts exceeded and EMI surplus；Also, pass through the direct current for being connected on rectification module The second inductance between cathode output end and electric heater, the third capacitor and with the input and output end that are attempted by rectification module Four capacitors form low pass LC filter together, can by electric heating utensil during heating caused by the differential mode of low frequency make an uproar Sound also filters out, wherein since the 4th capacitor and the second inductance are equipped with the DC output end in rectifier bridge, so that EMI noise It only recycles and filters out in the DC side of rectification module as far as possible, reduce the noise of conduction to rectification module exchange end and power grid；By This, works along both lines, and efficiently solves the problems, such as that common mode, differential mode conduct exceeded, EMI surplus deficiency, has ensured electric heating utensil energy Enough pass through conduction test；Also, selected electronic component is low in cost in the EMI suppression circuit, thermal losses is low and occupies It is small in size, which is promoted and applied in various electric heating utensils.

The purpose of the utility model embodiment another aspect be to provide it is a kind of it is low in cost, thermal losses is low and can effectively mention The DC power supply of the EMI surplus of high electric heating utensil.

To achieve the goals above, on the other hand the utility model embodiment provides a kind of DC power supply, including：Above-mentioned Electromagnetic interference EMI suppression circuit for electric heating utensil；And rectifier bridge, the exchange firewire input terminal of the rectifier bridge with exchange Zero curve input terminal is separately connected the firewire and zero curve of AC power source, for the alternating current of the AC power source to be converted to direct current And it is exported via the direct-flow positive pole output end of the rectification module and direct current cathode output end.

The purpose of the another aspect of the utility model embodiment is to provide a kind of electric heater of EMI surplus with higher Tool.

To achieve the goals above, the another aspect of the utility model embodiment provides a kind of electric heating utensil, including：Electric heating Device and heated object；And above-mentioned DC power supply, for powering for the electric heater.

Optionally, the electric heating utensil is electric cooker, wherein the heated object is the magnet steel that can contact electric cooker Interior pot, and the magnet steel connect power ground.

Optionally, the electric heater includes electric heating coil disk and/or electromagnetic heating induction coil disk.

Optionally, the electric heating utensil includes that the electric heating boilers of bottom-heated type and the electric heater are located at institute State the bottom of electric heating boilers.

Optionally, the electric heating utensil includes any one in following：Electric cooker, electric pressure cooking saucepan, electromagnetic oven, IH are broken Wall machine or cooking machine.

The electric heating utensil provided by the utility model embodiment and above-mentioned EMI suppression circuit are compared with the existing technology Possessed advantage is identical, and details are not described herein.

The other feature and advantage of the utility model embodiment will give in the following detailed description section specifically It is bright.

Detailed description of the invention

Attached drawing is to further understand for providing to the utility model embodiment, and constitute part of specification, It is used to explain the utility model embodiment together with following specific embodiment, but does not constitute to the utility model embodiment Limitation.In the accompanying drawings：

Fig. 1 is the circuit connection diagram of the EMI suppression circuit of an embodiment of the present invention；

Fig. 2 is the structural schematic diagram of the electric heating utensil of an embodiment of the present invention.

Description of symbols

PE power ground ACL AC power source firewire

ACN AC power source zero curve U rectification module

H electric heater C1, C2, C3, C4 capacitor

10 DC power supply of L1, L2 inductance

20 electric heating utensil, 201 driving device

202 IGBT, 203 electromagnetic heating induction coil disk

R1, R2 resistance B heated object

Specific embodiment

It is described in detail below in conjunction with specific embodiment of the attached drawing to the utility model embodiment.It should be understood that It is that specific embodiment described herein is merely to illustrate and explains the utility model embodiment is not limited to this reality Use new embodiment.

Term " first ", " second " are used for description purposes only in the description of the present invention, and should not be understood as indicating Or it implies relative importance or implicitly indicates the quantity of indicated technical characteristic." first ", " second " are defined as a result, Feature can explicitly or implicitly include at least one of the features.In the description of the present invention, the meaning of " plurality " is At least two, such as two, three etc., unless otherwise specifically defined.

As shown in Figure 1, the EMI suppression circuit for electric heating utensil is provided with first capacitor C1, the second capacitor C2, first Inductance L1, first resistor R1 and second resistance R2.Wherein the EMI suppression circuit is associated with setting with rectification module U and electric heater H, The exchange firewire input terminal and AC neutral line input terminal of rectification module U are separately connected the firewire and zero curve of AC power source, are used for The alternating current of the AC power source is converted into direct current；And rectification module U is used to power for electric heater H, the electric heater H is used to provide heat for heated object B.It should be noted that the heating type of electric heater H can be direct current electric heating type (such as Directly powered by the positive and negative anodes output end of rectification module), be also possible to AC electric-heating type (such as rectification module output end warp Implement inversion driving power supply indirectly by such as IGBT), and belong to the protection scope of the utility model.In addition, this is heated The type of body B can be it is diversified, can be it is corresponding with the type of electric heating utensil, such as when electric heating utensil be electricity When pressure cooker, which can be metal pan；When electric heating utensil is electric cooker, which can be interior pot Etc..

For the sake of security, the heated object direct or indirect connection of the electric heating boilers in the utility model embodiment For power ground (i.e. PE line) to be grounded, caused safety problem may be touched by people by thereby eliminating heated object.With Electric heating utensil illustrates for electric cooker, and in running order inner pan of electric cooker is contacted with magnet steel, correspondingly should PE line can be connection magnet steel and be indirectly connected to interior pot to realize.But present inventor is in the process for practicing the application While middle discovery PE line is drawn from heated object, the EMI noise at power interface is also increased.Therefore, it is highly desirable pair The safety-type electric heating boilers propose new EMI Restrain measurement, to ensure the Electro Magnetic Compatibility of electric heating utensil.

About the specific connection relationship of the EMI suppression circuit in the utility model embodiment, it can be first capacitor C1's Both ends bridge PE line and the AC neutral line input terminal of rectification module U respectively；The friendship of second capacitor C2 bridging PE line and rectification module U Filariasis line input terminal；And first inductance L1 be connected between PE line and heated object B, wherein inductance L1 is relative to capacitor C1 It should be not construed as limiting with the link position of C2, can be the side as shown in Figure 1 in capacitor C1 and C2, also can also be connection ((not shown)) between C1 and C2 etc.；First resistor R1 and second resistance R2 is parallel resistance pair, and the parallel resistance is to series connection In the connection line of first capacitor C1 and the second capacitor C2 and power ground PE.Pass through C1, C2, L1 and parallel resistance as a result, RLC low-pass filter is formed to R1 and R2 together, the common-mode noise sensed on PE line can be effectively filtered out, more particularly to frequency Rate has outstanding inhibiting effect in the high frequency common mode noise of 150KHz-30Mhz.

It should be noted that the differential mode noise of generated middle low frequency is for product during the work of electric heating utensil There is also certain influences for the superiority and inferiority of EMC Electro Magnetic Compatibility, also do not have or have ignored for electric heating utensil in the prior art The processing of generated differential mode noise during heating.

In view of this, EMI suppression circuit as shown in Figure 1 also discloses the technical solution for inhibiting differential mode noise, it is specific to go back Comprising the second inductance L2, third capacitor C3 and the 4th capacitor C4, wherein the exchange firewire of third capacitor C3 bridging rectification module U is defeated Enter end and AC neutral line input terminal, the second inductance L2 be connected on rectification module U direct current cathode output end V- and electric heater H it Between and the 4th capacitor C4 bridging rectification module U direct-flow positive pole output end V+ and direct current cathode output end V-.Inductance as a result, L2 and capacitor C3, C4 form LC low-pass filter, can effectively filter out the differential mode that electric heater H is conducted during the work time and make an uproar Sound improves the EMI surplus of electric heating utensil entirety；Wherein, capacitor C4 and inductance L2 is laid in the direct current output of rectification module End, can allow noise only recycle and filter out in the DC side of rectification module, reduce as far as possible the exchange end conducted to rectification module and The noise of AC network.Also, the low-pass filter as composed by inductance L2 and capacitor C3, C4 effectively can inhibit frequency to exist The middle low frequency differential mode noise of 9KHz-150Khz；EMI suppression circuit provided by the utility model embodiment is low in as a result, The EMI noise of frequency difference mould and high frequency common mode all has good inhibiting effect, improves electric heating appliance product and passes through EMC electromagnetism The qualification rate of compatibility test result.

Specifically, the first inductance L1 and the second inductance L2 can be filter inductance, can generally use ferrite material Material can be with it is also possible to can be using other materials, such as the filter inductance using common iron powder magnetic core material inductance It is amorphous material inductance, also can also be the alloy core inductance comprising iron silicon material inductance, iron sial material inductance.And The carrier of the EMI suppression circuit can be PCB printed circuit board.About the type selecting of first resistor and second resistance, can be Select strong antijamming capability, the good Chip-R of high frequency characteristics.

Although embodiment shown in FIG. 1 has been illustratively described the related component of EMI suppression circuit, it is to be understood that Be, to attached by it other function unit or module should also be as being included it is within the protection scope of the present utility model, such as IGBT (the Insulated Gate being connected with electric heater H is also provided in the circuit loop of electric heating utensil Bipolar Transistor, insulated gate bipolar transistor), and electric heater H work is controlled by it.

In order to realize that the electric heating utensil for being equipped with the EMI suppression circuit can be in the environment of power frequency (50Hz) AC power source Under can have preferable EMI surplus and anti-electromagnetic interference capability, the utility model embodiment also discloses in EMI suppression circuit The specific type selecting parameter of each component.First capacitor C1 and the second capacitor C2 is Y capacitance, and capacitance can be 100pF- with type selecting The capacitance of 4700pF；And third capacitor C3 can be filter condenser, can be has bigger electricity relative to C1 and C2 The safety capacitor of capacity, such as can be 1 μ F-10 μ F, and the filter condenser can be a capacitor, be also possible to by more The capacitor of a more small capacitances amount passes through composed by parallel connection, and when filter condenser is formed using multiple small capacitances parallel ways When, it can more significantly improve the working effect of the filter condenser.

A kind of example of DC power supply 10 of the utility model embodiment is also shown in Fig. 1, the DC power supply 10 packet Containing the electromagnetic interference EMI suppression circuit as described in foregoing embodiments and rectification module U.Specifically, rectification module U can To be rectifier bridge, it can also be that rectifier bridge plays the additional device of rectification effect with other.And as Fig. 1 also shows one kind Electric heating utensil 20, the electric heating utensil 20 include electric heater H and DC power supply 10.Specifically, electric heater H can be electricity and add Heat coil disk also can also be electromagnetic heating induction coil disk or combinations thereof, and the coil-type of electric heater H, which can be, to be depended on The heating method of the electric heating utensil 20, such as when electric heating utensil 20 has electromagnetic induction heating (IH, Induction Heating) when mode, electric heater H, which can be, selects electromagnetic heating induction coil disk.

It should be noted that IGBT (Insulated Gate can be passed through in the course of work of IH type electric heating utensil Bipolar Transistor, insulated gate bipolar transistor) output power is controlled to electromagnetic heating induction coil disk to be formed Oscillating circuit, and externally export oscillator signal；Wherein, a part of the oscillator signal is transmitted by rectifier bridge to power interface, And another part is electrically heated utensil and picks up to form vortex, to heat the food inside utensil；But in this heating process In, there are portion of energy, and power grid can have been arrived along conducting wire reverse transfer, i.e., a part is radiated in the form of electromagnetic field to space, separately Part energy is conducted by the ground wire of cookware to power grid, and the above can all cause the electric heating utensil that can not pass through high standard Quasi- conduction test, and electric heating utensil is caused to be unable to satisfy the requirement that EMI is tested.

The structural schematic diagram of the electric heating utensil 20 of an embodiment of the present invention as shown in Figure 2, the electric heating utensil 20 include driving device 201, the IGBT 202 connecting with driving device 201, the electromagnetic heating line of induction connecting with IGBT 202 Enclose disk 203 and the DC power supply 10 for exporting direct current.Wherein, driving device 201 is used for output drive signal, IGBT 201 For receiving the driving signal, and the work of electromagnetic heating induction coil disk 203 and heating can be controlled according to the driving signal. Details and effect about DC power supply 10 can refer to description above, so that 20 energy of electric heating utensil shown in Fig. 2 The high-frequency noise by PE line is enough effectively filtered out, and reduces the magnetic field strength to the electromagnetic field of external radiation, more than the EMI for improving product Amount and anti-electromagnetic interference capability.It should be noted that the drive of the driving signal shown in Fig. 2 about IGBT and offer driving signal Dynamic device is exemplary, IGBT be also based on other modes control electromagnetic heating induction coil disk work and heating, And belong to the protection scope of the utility model.

The utility model embodiment one side using upper, electric heating utensil 20 can be various electroheating type household electrics Device, such as can be electric cooker, electric pressure cooking saucepan, electromagnetic oven, IH wall-breaking machine, cooking machine or insulating pot etc..The utility model is real Applying example especially can be applied in the electric heating boilers of bottom-heated type, in these bottom-heated type electric heating boilers, add Hot device is positioned at the bottom of electric heating boilers.It should be noted that in the prior art, PE line is merely able to play the work of protection With, but EMI noise also can guide via PE line or be transferred to power interface simultaneously, and the Electro Magnetic Compatibility of product is caused to reduce；? After applying technical solution disclosed in the utility model embodiment, so that electric heating utensil 20 will not lead to EMI noise Power interface, but by the noise reverse leading and can filter out, thus improve the anti-electromagnetic interference capability of product.

About explanation of the implementation of the utility model embodiment in terms of economic benefits, in the EMI of current household appliances Common mode inhibition device used in circuit design, price usually all more than a yuan, produce in components in household electrical appliances Belong to the relatively high device of cost, and its anti-jamming effectiveness is not also significant, can not also ensure that electric heating utensil is carrying out conduction survey EMI surplus when examination can reach test request.In contrast, the electric heating utensil 20 in the present embodiment is above-mentioned due to using EMI Restrain measurement, under the premise of effectively inhibiting EMI noise, additionally it is possible to realize lower production cost, there is preferable market Promotional value.

The optional embodiment of the utility model embodiment, still, the utility model is described in detail in conjunction with attached drawing above Embodiment be not limited to the above embodiment in detail can in the range of the technology design of the utility model embodiment A variety of simple variants are carried out with the technical solution to the utility model embodiment, these simple variants belong to the utility model reality Apply the protection scope of example.

It is further to note that specific technical features described in the above specific embodiments, in not lance In the case where shield, it can be combined in any appropriate way.In order to avoid unnecessary repetition, the utility model is implemented No further explanation will be given to various combinations of possible ways for example.

In addition, any combination can also be carried out between a variety of different embodiments of the utility model embodiment, as long as It equally should be considered as the utility model embodiment disclosure of that without prejudice to the thought of the utility model embodiment.

Claims (10)

1. a kind of electromagnetic interference EMI suppression circuit for electric heating utensil, which is characterized in that the electric heating utensil includes electric heating Device, heated object and the rectification module for electric heater power supply, the exchange firewire input terminal and AC neutral line of the rectification module Input terminal is separately connected the firewire and zero curve of AC power source, for the alternating current of the AC power source to be converted to direct current and is passed through By direct-flow positive pole output end and direct current the cathode output end output of the rectification module and the heated object and power ground phase Connection, wherein the EMI suppression circuit includes：

First capacitor bridges the power ground and the AC neutral line input terminal；

Second capacitor bridges the power ground with described and exchanges firewire input terminal；

Third capacitor bridges the exchange firewire input terminal and the AC neutral line input terminal of the rectification module；

First inductance is connected between the power ground and the heated object；

Second inductance is connected between the direct current cathode output end of the rectification module and the electric heater；

4th capacitor bridges the direct-flow positive pole output end and the direct current cathode output end of the rectification module；

First resistor and second resistance, parallel with one another, the first resistor parallel with one another and second resistance are connected on described first In the connection line of capacitor and second capacitor and the power ground.

2. circuit according to claim 1, which is characterized in that the carrier of the EMI suppression circuit is PCB printed circuit Plate.

3. circuit according to claim 1, which is characterized in that the first resistor and the second resistance include patch electricity Resistance.

4. circuit according to claim 1, which is characterized in that the first capacitor and the capacitance of second capacitor are big It is small be the capacitance of 100pF-4700pF and the third capacitor size be 1 μ F-10 μ F.

5. a kind of DC power supply, which is characterized in that including：

Such as the electromagnetic interference EMI suppression circuit of any of claims 1-4 for electric heating utensil；And

Rectifier bridge, the exchange firewire input terminal and AC neutral line input terminal of the rectifier bridge are separately connected the firewire and zero of AC power source Line, for the alternating current of the AC power source to be converted to direct current and via the direct-flow positive pole output end of the rectification module and directly Flow cathode output end output.

6. a kind of electric heating utensil, which is characterized in that including：

Electric heater and heated object；And

DC power supply as claimed in claim 5, for powering for the electric heater.

7. electric heating utensil according to claim 6, which is characterized in that the electric heating utensil is electric cooker, wherein institute Stating heated object is the interior pot that can contact the magnet steel of electric cooker, and the magnet steel connects power ground.

8. electric heating utensil according to claim 6, which is characterized in that the electric heater include electric heating coil disk and/ Or electromagnetic heating induction coil disk.

9. electric heating utensil according to claim 6, which is characterized in that the electric heating utensil includes bottom-heated type Electric heating boilers and the electric heater are located at the bottom of the electric heating boilers.

10. electric heating utensil according to claim 6, which is characterized in that the electric heating utensil includes appointing in following Meaning one：Electric cooker, electric pressure cooking saucepan, electromagnetic oven, IH wall-breaking machine or cooking machine.